氯化氢事故性泄漏扩散的后果模拟分析

Simulation analysis on accident consequence of hydrogen chloride leakage and dispersion

通过对1起BOC(叔丁氧羰基)生产中误操作造成的氯化氢泄漏事故的后果模拟分析,说明扩散模型与后果伤害模型对预测事故伤亡后果和人员应急响应策略选择的作用。首先确定事故中氯化氢的泄漏量和泄漏方式,采用高斯烟团模型模拟扩散过程,利用室内外换气公式,得出室内外氯化氢气体质量浓度随时间变化的关系,然后结合概率函数法得出室内外暴露剂量以及概率变量随时间变化的关系。模拟结果表明,室内外的概率变量都小于-7,因此人员死亡概率为0,与事故实际造成的后果基本相符。因此,选择相应的扩散模型与后果伤害模型对毒气泄漏事故进行后果模拟分析,能定量确定泄漏事故对特定范围内造成的危险程度,预测事故伤亡后果。

The paper is aimed to show that dispersion model and consequence model are useful for predicting accidents consequences and choosing emergency response strategy. For this purpose, an example of hydrogen chloride leakage incident which was caused by disoperation during BOC production process was chosen and the consequences of the accident was tried to be analyzed. First of all, it was of great need to point out the amount and the leakage mode of hydrogen chloride in the accident. The simulation experiment was used to determine the amount of BOC. Then, the leakage of hydrogen chloride for 3.0 - 4.5 kg could be calculated based on the chemical reaction equation and the leakage mode for instantaneous leakage was determined. According to the nature of hydrogen chloride, the dispersion process was simulated by using Gaussian puff model. The diffusion coefficients were determined based on the conditions of weather. Later on, the indoor-outdoor hydrogen chloride time-varying concentrations were calculated through indoor and outdoor air change formula. A conclu- sion could be drawn from the results that people who close to the leakage source normally evacuate from the scene of accident too late. For that case, closing the doors and windows immediately and staying indoors were effective options when the instantaneous leakage occurs. The exposure dose and probit variables change with time were studied with the probability function method. Simulation results showed that the probit variables did not exceed - 7, so the probability of death was 0. The accident has caused some students having aspiration reaction; including 32 students have been admitted to hospital. And the results of the simulation were in agreement with the consequences of real incident. Therefore, appropriate dispersion model and consequence model are useful for simulating the toxic gas release incident. The simulation result will be helpful for quantitatively determination of the hazardous degree of leakage accident in specific areas; prediction of casualties, selection of emergency response strategy and minimization of incidents injures.